Breathing apparatus



Dec. 7 1926.

M. VON DER HEIDE BREATHING APPARATUS Filed July 8, 1924 Fig.1.

firm

Patented Dec. 7, 1926.

UNITED STATES 1,609,977 PATENT OFFICE.

MAX VON'DER HEIDE, OF KIEL, GERMANY.

BREATHING APPARATUS.

Application filed July 8, 1924, Serial No. 724,816, and in Germany December 14, 1921.

This invention relates in general to breathing apparatus and more particularly to a device for preventing an excessive admixture of gas which is unsuitable for respiration t'rom accumulating in a breathing appara-- tus in which the breathing gas is automatically renewed as the oxygen is consumed.

In apparatus of this kind only the oxygen consumed in the lungs of the user of the apparatus is replaced, while the adn'iixtures contained with the oxygen in the high pressure oxygen flask are not consumed by the .lungsand get into the breathing conduits ot the apparatus and collect in the breathing bag or in the valve control bag arranged ad jacentto-the breathing bag. Therefore the bag so affected soon be. orncs charged to such an extent with these admixtures, which it is impossible to avoid in the production of oxygen, that the bag is prevented from collapsing sufiiciently to actuate'the valve control device arranged in it. Arrangements have therefore been provided the object of which is to prevent the quantity of these admixtures in the. apparatus from exceeding a certain amount. Such an arrangement comprises a pressbutton valve on the breathing bag by means of which the user of theapparatus can allow a portion of the content of the bag to escape from time to time, the quantity of gas discharged in this manner being immediately replaced through the automatic controlling device by :1 corresponding quantity of oxygen from the high pressure flask. The principal objection to this arrangement is that the user of the apparatus must pay careful attention to the pressure valve, this attention being necessary just at a time when he is working hardest, i. e. when the danger of suffocation through want of oxygen in the breathing bag is greatest. Theill effects due to lack of oxygen appear so sudden'and without warning, that the user of the apparatus will often not be able to actuate the valve.

Another arrangement for avoiding the danger of suffocation through the aforementioned cause involves the maintenance of a constant flow of oxygen (about 1.5 liters per minute) in addition to the oxygen automatically admitted into the respiration conduits. A breathing apparatus provided with an arrangement of this kind substantially constitutes a reducing valve apparatus old in the art into which an additional supply of oxygen is automatically introduced only at times when unusually large amounts of oxygen are required. As soon as the oxygen needed exceeds the quantity that is kept constantly flowing, the danger of the breathing bag being surcharged with admixtures unsuitabletor breathing will arise as explained above. Thus, wnen this arrangement reduces the danger of suffocation, it does not entirely remove it. a

The atoredescribcd problem is solved by the present invention in a very simplemanner by caus ng the pressure that arises at each expiration in the conduits of the apparatus to give rise to an escape of a quantity of air that corresponds to the quantity expired, so that the quantity of oxygen admitted by the automatic controlling device is larger than the amount of oxygen consumed by the lungs of the user of the aj 'iparatus. In this manner the percentage of oxygen in the breathing air of the apparatus may be kept constant. I

A device for reducing to practice the novel idea 0? replacing the oxygen may comprise a relief valve combined with the mouth piece and enclosed in a chamber whose interior is connected with the external air through a small opening.

constructional form of the device is shown in the drawing in which Fig. l is a vertical central section of :a mouth piece with shortconnecting pipes and valve chamber and V Fig. 2 illustrates the layout of a complete breathing apparatus. 7

As shown'in Fig. 1 the mouth piece cen nector which may be of any suitable form, consists in the present example of a cylindrial body a with which are combined two short connecting studs 7) and 0 to which the breathing gas conduits or pipes are attached and' a short oblong pipe (Z tor connection with the mouth piece proper. l-ittached to one. side or end of the cylindrical body a is a chamber or cap 6 containing the automatic rinsing or escape valve consisting of a valve plate f which is pressed by a spring 9 against its seat 72,. The chamber e has an opening 0 connecting its interior with the external air.

Atthe other end of the chamber 6 is disposed a self-closing valve whose plate 2' closes the chamber 6 against the external air. Connected with the valve plate z' is a spindle whose free end carries a push-button Z. The latter is hollow, enabling it to form a guide for a pring m which tends to press the valve against its seat. By pressing the button Z the valve 71 is opened against the action of the spring on.

The press-button valve may be dispensed with and the chamber 0 may be entirely closed except at the small opening 0. The press-button valve may be used for permit ting any desired quantity of breathing air to escape from the apparatus, the discharged quantity being automatically replaced from the oxygen flask. This is a convenient means for renewing the entire air content of the apparatus in a few moments in special cases. As a rule this valve is unnecessary in breathing apparatus in which a so-called bypass valve is arranged collaterally with the pressure reduction valve and through which oxygen may be admitted by Way of a branch pipe into the breathing conduit from the high pressure flask.

In breathing apparatus without a by-pass valve the press-button valve may serve as a safety valve by which gas may be let oil through pressing the button Z, whenever the pressure in the breathing conduit is unduly large and makes it difficult for the user of the apparatus to exhale. I

The relief valve f in the chamber 6 is constructed so that it oifers less resistance than that offered by the conduits of the apparatus. Hence at each expiration the valve f is lifted from its seat it and a part of the expired air passes through the opening 0 into the atmosphere. The quantity of air which thus escapes is determined by the size of the opening 0 in the chamber a and the resistance of the relief valve. It also depends on the gas pressure produced during expiration. The amount of air discharged is thus ultimately a measure of the Work of the user of the apparatus because this work is proportional to the amount oi oxygen replaced in the air used by the lungs.

Theoretical and practical investigations of the aforedescribed manner of scavenging the air conduits in breathing apparatus have shown that the quantity of scavenging gas required is so small that it hardly affectsthe length of time for which the apparatus can be used. The arrangement according to the invention also renders it pos sible to use oxygen of very different degrees of purity (the degree prescribed by the Government is 98%) WltllOLllJ risk of surcharging the breathing apparatus with ad mixtures unsuitable for breathing.

I claim 1. In a breathing apparatus, an air purilier, a mouth piece, conduits for conducting air from the mouth piece to the purifier and from the purifier to the mouth piece and an outwardly operating spring pressed relief valve closely adjacent to said mouth piece and free y communicating with the outside atmosphere, said relief valve responding to the exhalation pressure produced in said conduits at each exhalation for allowing a desired quantity of exhaled impure air to escape into the external atmosphere, said quantity corresponding to the exhalation pressure.

2. In a breathing apparatus, an air purifier, air conduits for conducting air to and from the purifying device, a mouth piece attached to said conduits, a chamber located adjacent to said mouth piece and having a small opening for establishing communication between the interior of the chamber and the external atmosphere and a relief valve disposed between the mouth piece and the chamber and being responsive to the pressure produced at each exhalation for establishing communication a between said mouth piece and conduits and said chamber, for discharging a quantity. ofexhaled air from the mouth piece directly into the external atmosphere, said quantity corresponding to the exhalation pressure.

3. In a breathing apparatus, an air puriher, a mouth piece, conduits for conducting air from the mouth piece. to the purifier and from the purifier to the mouth piece and an outwardly operating spring pressed:

relief valve between the mouth piece and the purifier and freely communicating with the outside atmosphere, said relief valve responding to the exhalation pressure produced in said conduits at each exhalation for allowing a desired quantity of exhaled impure air to escape into the external atmosphere, said quantity corresponding to the exhalation pressure.

In testimony whereof I affix my signature.

MAX VON DER HEIDE. 

